<?php 

  $nonce=$_GET['nonce'];
  $timestamp=$_GET['timestamp'];
  $token="wzp";
  $signature=$_GET['signature'];

  $arr=array($timestamp,$nonce,$token);

  sort($arr);

  $str=sha1(implode($arr));
 if($str==$signature){
 	echo $_GET['echostr'];
 	exit;
 }  
